The applicant has conducted basic research and published extensively on the late phase allergic reaction, a response that is considered to be critical to the development of the chronic symptomatology that is present in such diseases as atopic dermatitis, allergic rhinitis, and most importantly, asthma. He has developed a rat animal model to study the pathogenesis of the late response and is now in a position to address selected important issues related to the immunologic, physiologic and biologic events critical to the development of late pulmonary allergic reactions. In addition to his independent research in this area, he has combined his knowledge of late asthmatic responses with that of his colleagues (at the University of Wisconsin), who are studying the effects of viral infections on asthma, to investigate the mechanisms by which viral upper respiratory infections predispose individuals to the development of late asthmatic responses and airway hyper-responsiveness. Thus, two important aims of this project are first (immediate goal), to identify, in ways not as readily possible in other animal models, the contribution of IgE antibody and mast cells to the events that transpire following the induction of the pulmonary allergic reaction; and second (more long term goal), to ascertain the effects that viral infections have on airway inflammation, airway mechanics, and airway responsiveness in relationship to the pulmonary allergic reaction.